It’s happened to me many times before; poured in salt through the larger opening, misread the amount of salt required or even just zoned out while pouring in the salt. Here’s a quick, easy and quite effective fix for the problem. Sadly though, it only works with sauces, soups, stews etc.
Simply peel a large potato for every 1-1.5L of food and chop into large chunks and place in the stew. Let everything simmer together for about 20-30mins and the potatoes are well cooked. The potato should have absorbed some of the salt, so simple pick the potato chunks and discard (or eat) and re-season your food as desired.